Multiple tube coil unit



June 27, 1939. c, DEVERALL 2,163,591

MULTIPLE TUBE COIL UNIT Filed June 5, 1937 Patented June 27, 1939 MULTIPLE TUBE COIL UNIT Charles N; Devcrall, Buffalo, N. Y., assignor to Niagara Blower Company, New York, N. Y., a corporation of New York Application June 3, 1931, Serial- No. 146,225

Claims.

This invention relates to a coil unit for refrigerators and more particularly to a unit of this character which operates to cool air as part of an air conditioning apparatus.

In such refrigerators or coolers the refrigerant employed, such as Freon, ammonia, ethyl chloride or the like, is usually forced while in liquid form past an expansion valve into the inlet of a coil so that it is converted into gas or vapor which expands in the coil and thereby produces a cooling effect on the atmosphere around the coil, after which the gas is again cooled in a condenser and converted into liquid form preparatory to being again returned to the coil in vapor form.

Heretofore the coil unit of this type usually consisted of an inlet header or manifold, an outlet header or manifold, and a plurality of cooling tubes having their inlet and outlet ends connected respectively with said inlet and outlet headers.

These prior refrigerators are unsatisfactory due principally to the absence of any provision for maintaining a balanced or even flow of the refrigerant through the several tubes of the coil so that it was impossible to secure the maximum efficiency of the apparatus at all times.

The object of this invention is to balance the flow of the refrigerant through the several cooling tubes of the coil unit and thus equalize or evenly distribute the cooling effect over the entire cluster of tubes and secure the maximum emciency of the coil unit.

With this end in view this invention consists generally in providing a control device between the inlet end of each cooling tube and the inlet header which is so constructed that it can be adjusted to produce an orifice of the required size for supplying the requisite quantity of refrigerant to the respective tube to insure a balanced flow of refrigerant through the several tubes of coil unit and unalterably fixlng the size of this orifice after the same has been correctly attained, thereby preventing disturbance of this balanced flow of the refrigerant and avoiding the necessity for any further adjustment of this flow during the subsequent operation of the apparatus.

In the accompanying drawing:

Fig. 1 is a perspective view of an approved.

form of coil unit for refrigerators embodying my invention.

Figs. 2 and 3 are fragmentary sections on an enlarged scale, taken on the correspondingly numbered lines in Fig. 1. 1

Fig. 4 is a cross section taken on line 4-4- Fig. 2.

Fig.5 is a horizontal longitudinal section taken on line 55, Fig. 1.

Fig. 6 is a section similar to Fig. 2, showing a modified form of my improvements.

In the following description similar characters of reference indicate like parts in the several figuresof the drawing.

In its general organization the coil unit comprises an upper inlet header or manifold I 0 adapted to receive the refrigerant, a lower outlet header or manifold I l adapted to discharge the refrigerant and a plurality of cooling tubes I! connected at their upper inlet ends with the inlet header and at their lower outlet ends with the outlet header, and adapted to conduct the refrigerant from the inlet header to the outlet header. a

The refrigerant employed in this coil unit may be any of those now commonly used for refrigeration such as Freon, ammonia and ethyl chloride which ar alternately liquefied and gasifled during the refrigerating operation of the apparatus of which the present coil unit forms a part.

As shown in the drawing both the inlet header and the outlet header have the form of cylinders which are constructed of sheet metal and arranged horizontally and parallel one above the other, and the cooling tubes are of serpentine or zig-zag form but the particular shape of these members is of no importance so far as the merits of the present improvements are concerned.

At one end the inlet header is provided with an inlet pipe l3 through which the refrigerant is conducted into this header. The pipe is provided with the usual expansion valve which receives the liquid refrigerant under pressure and releases the same in the form of a gas or vapor which'latter enters the inletheader and then it passes through the cooling tubes and into the outlet header. During the passage of the cold gaseous refrigerant through the tubes the same absorbs the heat in the atmosphere outside of the tubes and thus lowers the temperatures around the coil unit for refrigeration purposes.

At one end of the outlet header the same is connected by a sleeve I 4 with a discharge pipe I! which leads to a compressor (not shown) in which the gas is compressed and thence passed to a condenser for completing the liquefaction of the gaseous refrigerant preparatory to again passing the same to said expansion valve and and thus produce a leak-tight joint between" these members.

In order to secure the maximum efiiciency of the coil unit the flow of the refrigerant through the several tubes should be balanced so that each of the tubes will produce the required refrigerating effect and thereby equalize or distribute the refrigerating load over the entire coil unit so that the surrounding atmosphere is cooled most advantageously. A uniform or balanced distribution of the cooling effect of the coil unit is produced by setting the inlet orifice of each cooling tube so as to definitely determine the amount of refrigerant which can pass through the same from the inlet header to the respective tube according to the refrigerating load which the same should carry and then fixing this orifice so that this load cannot be changed but will always be the same and thus permit the cooling capacity of this tube with reference to other tubes in the cluster or group to remain undisturbed.

Various means may be employed whereby the inlet orifices of the several cooling tubes may be individually set at a selected capacity and then fixed to prevent this capacity from being easily changed. Satisfactory means for this purpose are shown in Figs. 1, 2 and 4 and constructed as follows:

The numeral I8 represents a control nipple or tubular member which extends across the interior of the inlet header and has its front and rear ends projecting through openings i9, 20 formed on the diametrically opposite sides of this header, as shown in Fig. 2. The rear opening 20 in the inlet header is surrounded by an annular flange 2| projecting laterally from this header and a leak-tight joint is produced between the same by welding, as shown at 22 in Fig. 2. The inlet end of the respective cooling tube projects into the rear end of the nipple i8 so that the latter, in effect, becomes a forward extension or part of this tube and a leak-tight joint is formed between this nipple and tube by slightly flaring the rear end of this nipple, as shown at 23 in Fig. 2, and welding this flaring part to the adjacent peripheral portion of the respective tube, as shown at 24 in the same figure.

Surrounding each front nipple opening I9 in the inlet header and projecting laterally from the same is a collar or tubular neck 25 which is connected at its inner end with this header by a welded joint 26 so as to virtually form a part of this header, as shown in Fig. 2. The central part of the bore of this tubular neck is reduced to form a bearing opening 21 of comparatively small diameter while the inner part of this bore is enlarged to form an inwardly facing shoulder 28 the peripheral part of which is engaged by the front end of the control nipple. as shown in Fig. 2, and the outer part of this bore is also enlarged to form a pocket 29 for use as a stumng box, as will presently appear.

On one side of the control nipple and within the inlet header the same is provided with a control orifice opening or port 30 for the passage of refrigerant from this head to the interior of the nipple and to the respective cooling tube. The size or capacity of this orifice may be adapted to permit a definite amount of the refrigerant to pass through the same as may be determined to secure a balanced distribution of the refrigerant throughout the entire coil unit and obtain the desired equalization of cooling effect of the refrigerant on the atmosphere passing the coil unit. For this purpose means are provided for varying the capacity of the orifice 30 and this may be accomplished by a control plug 31 which is fitted within the control nipple and provided with a control port 32 one end of which opens rearwardly into the nipple and toward the respective cooling tube while the other end opens laterally on the periphery of this plug opposite the control orifice of the control nipple, as shown in Figs. 2 and 3.

When the control plug 3| is turned so that its port 32 is fully in register with the control orifice 30 in the nipple l8, as shown by full lines in Fig. 4, then the maximum amount of refrigerant is capable of passing through this orifice from the interior of the inlet header to the respective cooling tube, but when this plug is turned so that its port is partly out of complete register with the control orifice, as shown by dotted lines in the same figure, then the size of the control orifice is shut off or reduced and its capacity for conducting refrigerant from the inlet header to the respective cooling tube is cut down accordingly. By thus turning the several control plugs in the control nipples from the normal or fully registering positions to more or less incomplete registering positions relative to the several control orifices the sizes of the latter may be accurately adapted to suit the requirements necessary for producing an equal, uniform or balanced distribution of the refrigerant over the entire coil unit for securing the most efllcient refrigerating effect during the operation of the apparatus.

In the construction shown in Fig. 2 the front or outer end of the control plug engages with the inwardly facing shoulder 28 of the neck 25 and turning of this plug for determining the effective area of the control orifice is effected by means which extend to the exterior of the apparatus so that adjustment of the size of this orifice may be effected while the apparatus is in operation. The preferred means for this purpose comprises an operating stem 33 of smaller diameter than the plug projecting outwardly from the outer end thereof through the bearing opening 21 in which it is journaled and through the pocket 28 and terminating in front of the neck 25. Turning of the control plug may be effected by various means, for example, by a wrench or similar tool applied to the outer square end 34 of the plug stem, as shown in Figs. 2 and 4.

A leak-tight joint may be produced between the plug, stem and the neck of the orifice control device by a soft packing 35 arranged within the pocket 28 around the stem and a gland 36 surrounding the stem and connected by a screw joint 31 with the neck and engaging its inner end with this packing, as shown in Fig. 2.

After the control plug has been turned into the required position for securing a control orifice of the desired size means are provided which render it normally impossible to change the size of this orifice and thus leave the same in a fixed condition so that thereafter a balanced distribution of the cooling eflect of the coil unit will be maintained without requiring any further attention.

Various protective means may be provided for accomplishing this purpose, those shown in Fig. 2 being so organized that the operating stem is normally inaccessible and therefore not liable to tampering or interference. These protective means comprise a sealing cap or cover 38 secured by a screw joint 39 to the outer end of the neck and enclosing the outer end of the plug operating stem, and a packing ring, gasket or Washer 40 interposed between the front end of the neck 25 and the inner side of the protecting cap.

In the modified form of this invention shown in Fig. 6 the cooling tube 4| and the companion control nipple 42 are formed as one continuous piece of tubing which is secured in openings 43, 44 on opposite sides of the inlet header ID by welded joints 45, 46, the control plug 41 is turned by applyinga screw driver in a nick 48 formed in the outer end of the plug, the front end of the plug has an annular flange 49 engaging with the front end of the control nipple 42, and the plug is held against turning after adjustment and the joint between the .same and the control nipple is sealed by solder 50 connecting this flange and the taining a balanced flow of the refrigeranthas once been determined the same is fixed so that no further attention is required to maintain this.

flow in a balanced condition. This balancing can be very easily determined by supplying refrigerant to the unit and then observing on which tube the atmosphericmoisture first condenses or frosts and adjusting the orifices until they all become moist at the same time. If this method is not satisfactory a thermometer can be slipped on each tube and the orifices all adjusted until the readings are all the same. It will be observed that during such balancing, the construction of the adjustable orifices is such that no atmospheric air can enter the system, the moisture carried by such air being very troublesome as it is them inoperative.

Obviously this invention is also applicable to" coil units for heating andit is therefore to be understood that the herein described improvements may be embodied in heat exchangers which function either as coolers or heaters and that the term "cooling or its equivalent as herein used includes both forms of such heat exchangers.

I claim as my invention:

1. A coil unit for refrigerators comprising an inlet header adapted to receive a refrigerant, an outlet header adapted to discharge the refrigerant, a plurality of cooling tubes having opposite ends communicating with said inlet and outlet headers, and a control device whereby an orifice of a definite size is produced and fixed for establishing said communication between the interior of each tube and the inlet header, said control device including a hollow body having its interior communicating with the interior of the respective tube and provided with a port opening into said inlet header, and aplug movable in said body and provided with a port adapted to be moved into more or less register with the port in said body for producing such orifice and means whereby said plug is protected against displacement after the size of said orifice has been established.

2. A coil unit for refrigerators comprising an inlet header adapted to receive a refrigerant, an outlet header adapted to discharge the refrigerant, a plurality of cooling tubes having opposite ends communicating with said inlet and outlet headers and a control device whereby an orifice of a definite size is produced and fixed for establishing said communication between the interior of each tube and the inlet header, said control device including a tubular body having one end of its interior communicating with the interior of the respective tube and provided in its side with a port opening into said inlet header, a rotatable plug arranged in said body and provided with a port adapted to be moved into more or less register with the port in said body and the outer end of said plug being accessible from the exterior of said body and means for normally preventing access to the outer end of said plug.

3. A coil unit for refrigerators comprising an inlet header adapted to receivea refrigerant, an outlet header adapted to discharge the refrigerant, a plurality of cooling tubes having opposite ends communicating with said inlet and outlet headers and a control device whereby an orifice of a definite size is produced and fixed for establishing said communication between the interior of each tube and the inlet header, said control device including a tubular body arranged within theinlet header and having one end. of its interior communicating with the interior of the respective tube and provided, in its side with a port opening into the inlet header, a rotary plug arranged in said body and having a port adapted to be placed into more or less register with the port of said body for producing such orifice and also provided with an outwardly extending operating stem, a collar surrounding said body, plug and stem and secured to said inlet header, a stuflingbox mounted on said collar and surrounding said stem, and a cap secured to" said collar and covering the outer end of said stem.

4. A coil unit for refrigerators comprising an inlet header adapted to receive a refrigerant, an outlet header adapted to discharge the refrigerant, and a plurality of cooling tubes having inlet and outlet ends opening respectively into said inlet and outlet headers, and each of said tubes provided at its inlet end with a tubular member which extends across the inlet header and through opposite sides of the same and one end of which communicates with the respective tube and the side of which is providedwith an opening within the inlet header.

5. A coil unit for refrigerators comprising an inlet header adapted to receive a refrigerant, an outlet header adapted to discharge the refrigerant, a plurality of cooling tubes having inlet and outlet ends opening respectively into said inlet and outlet headers, and each of said tubes provided at its inlet end with a; tubular member which extends across the inlet header and through opposite sides of the same and one end of which communicates with the respective tube and the side of which is provided with an opening within the inlet header, a collar surrounding that end of the tubular member opposite to the opening port adapted to register more or less with the port in said tubular member and provided with an operating stem projecting through said collar and having a shoulder engaging the shoulder of said collar, a packing arranged between said stem and collar, and a gland surrounding said stern and screwed into said collar and bearing against said packing.

6. A coil unit for refrigerators comprising an inlet header adapted to receive a refrigerant, an outlet header adapted to discharge the refrigerant, a plurality of cooling tubes having inlet and outlet ends opening respectively into said inlet and outlet headers, and each of said tubes provided at its inlet end with a tubular member which extends across the inlet header and through opposite sides of the same and one end of which communicates with the respective tube and the side of which is provided with an opening within the inlet header, a collar surrounding that end of the tubular member opposite to the respective tube and secured to the adjacent part of the inlet header and provided with an internal shoulder, a rotary control plug arranged within the tubular member and provided with a laterally opening port adapted to register more or less with the opening in said tubular member and provided with an operating stem projecting through said collar and having a shoulder engaging the shoulder of said collar, a packing arranged between said stem and collar, a gland surrounding said stem and screwed into said collar and bearing against said packing, and a cap screwed on said collar and covering the outer end of said stem.

- '7. A coil unit for refrigerators comprising an inlet header adapted to receive a refrigerant, an outlet header adapted todischarge the refrigerant, a plurality of tubular members extending across the interior of the inlet header and each tubular member passing through openings in the opposite sides of the inlet header and provided in its side with an opening arranged within the inlet header, and a plurality of cooling tubes each having its inlet end arranged within one end of one of said tubular members and having its outlet end connected with the outlet header.

8. A coil unit for refrigerators comprising an inlet header adapted to receive a refrigerant, an outlet header adapted to discharge the refrigerant, and a plurality of cooling tubes each having its outlet end secured to the outlet header and having its inlet end extending across the inlet header and through opposite sides of the same and provided within the inlet header with a side opening.

9. A coil unit for refrigerators comprising an inlet header adapted to receive a refrigerant, an outlet header adapted to discharge the refrigerant, a plurality of cooling tubes each having one end secured to the outlet header and having its other end extending across the inlet header and through opposite sides of the same and provided within the inlet header with a side opening, and a control plug arranged in the interior of said other end of each tube and provided with an opening adapted to register more or less with the side opening of the respective tube and having a shoulder bearing against the adjacent extremity of said tube, said tubes being connected by welding to said headers, and each of said control plugs being fixedly connected to the respective tube for producing a fixed relation of the corresponding openings of said tubes and control plugs.

10. A coil unit for refrigerators comprising an inlet header adapted to receive a' refrigerant, an outlet header adapted to discharge the refrigerant, a plurality of cooling tubes having opposite endls communicating with said inlet and outlet headers, and a control device whereby an orifice of a definite size is produced and fixed for establishing said communication between the interior of each tube and the inlet header, said control device including a hollow body extending through one side of said inlet header and having its interior communicating with the interior of the respective tube and provided with a port opening into said inlet header, and a plug in said body 1 and provided with a port adapted to be originally moved into more or less register with the port in said body for producing such orifice and means arranged externally of said body and preventing ready manipulation of said plug.

CHARLES N. DEVERALL. 

